1. Field of the Invention
The invention is in the field of communications and more specifically in the field of signal repeaters.
2. Related Art
When signals are communicated over distances greater than the communication range of a single transmitter, the signal must often be relayed before being received at its intended destination. This strengthening may be performed by a repeater that receives the signal and promptly resends an amplified copy of the signal.
One problem with repeaters is that they are difficult to use when a signal is broadcast in networks that are not linearly structured. For example, if a network is in the form of a mesh or a ring, a repeater may itself receive a signal that it previously sent. This signal may thus be repeated indefinitely. In mesh networks including more than one repeater, copies of a signal may multiply when each signal sent by one repeater is received and rebroadcast by more than one repeater. This multiplication is referred to as a broadcast storm and may overwhelm a network.
Some systems have tried to avoid broadcast storms by ensuring that the network does not contain any loops. As such, these networks use a unicast or multicast algorithm such as the Spanning Tree Algorithm to transmit the signal to each of the nodes. In a unicast channel, a packet is transmitted to a particular destination, and other nodes in the vicinity do not decode the packet. However, this approach prevents the use of a broadcast channel in a network, and, therefore, may not be practical under some network standards.
Powerline communication networks are one example of mesh networks in which a broadcast storm could occur if repeaters were used. To avoid broadcast storms, repeaters are not used in powerline communications standards, such as the HomePlug AV standard. There is, therefore, a need for improved methods of avoiding broadcast storms, particularly in powerline communication networks.